Shravan is the fifth month of the Hindu calendar and it is considered as one of the auspicious month. According to Hindu calendar Shravan is month of rains and usually starts in mid July and lasts till mid August. Mostly Hindus do not eat non vegetarian food during Shravan.a
Here are some spiritual and scientific reasons why people avoid eating non-vegetarian foods during Shravan month.
1. Month of Festival
Shravan is month of festivals & celebrations like Rakshbandhan, Nagpanchami, Onam, Kajori Purnima and so on. During any auspicious festivals like Holi, Diwali or Chhath almost every religious person do not eat non-vegetarian food. The reason is that these days are dedicated and related to gods and are auspicious days. So these days, they must only have Satvik food(which excludes Garlic and Onion as well).
Shravan is a holy month of lord Shiva. All days in month are considered auspicious and each day there is a particular observance by a particular Hindu community.
2. Rain Born Disease
In this month in which monsoon are in full blast. The rains come with lot of water born disease like hepatitis, cholera, Gastritis etc. The general hygiene is very bad & you never know what type of infection you might catch. Most of people believe that meat/non-vegetarian food during this month has more chances of get infected.
3. Low Immunity Level
According to Ayurveda, during Shravan the immunity power is very low, so better to avoid non vegetarian, spicy, oily food during this season. Monsoon Diet must be lighter, warm, less watery etc.
4. The Breeding Season
Shravan is also month of Love & romance. This is not just a month of love for humans, but also for animals. This is their time of reproduction. It is breeding season for most of the animals. It is sin to kill animal when they are pregnant or hatching eggs.
One other reason could be that if you end up eating pregnant animals or eggs then there will be lack of meat/non-vegetarian food during the rest of years.
Those Hindus who do eat meat tend to avoid it during special religious days e.g. Ramanavami, Janmashtami, Navratri, Diwali, etc. and/or during certain special months like Shravan, Chaturmasya or Kartik etc. The question arises as to why there is avoidance on certain days and not on other days ?
One reason could be that they in fact know that eating meat is a sinful but they are unable to stop eating it. But at least they try to avoid it on special religious days due to fear of accruing more severe sins.